This invention relates to plasticized polyacrylonitrile compositions and the production of oriented plasticized polymer film. In particular, it relates to polyacrylonitrile (PAN) compositions and methods for applying a liquid polyether plasticizer to water-containing PAN substrates during film manufacture.
High nitrile polymers are employed in making packaging films, foils and sheets having good resistance to passage of oxygen and water vapor. PAN homopolymer film is an excellent gas barrier material; however for some applications, it lacks adequate flex-crack resistance in unmodified form, even after molecular orientation. Addition of an inert or non-hazardous plasticizer to improve flex performance, stress-strain properties, impact strength, etc. is desirable for food packaging or wrap film.
It is an object of the invention to provide an novel PAN plasticizer system. It is a further object of the present invention to provide this novel combination in film form. It is yet another object of the present invention to provide a facile process for the introduction of a particular class of liquid polyethers into the PAN polymer system.